#sign-person-on-duty {
    position: relative;
    left: 50%;
    transform: translate(-50%, 0);
    margin-top: 150px;
    width: 50%;
    min-width: 400px;
}

.sign-person-on-duty-card {
    display: inline-block;
    width: 10rem;
    height: 3rem;
    line-height: 3rem;
    box-shadow: 0 0 3px #DDD;
    border-radius: 10px;
    margin: 5px;
    background: rgba(255, 255, 255, 1);
}